Hypertensive encephalopathy

Emergency Medicine

Clinicals - History

Fact Explanation
History of hypertension Almost all patients have a history of hypertension. History of hypertension
Almost all patients have a history of hypertension.
Drug history Patients who are taking sympathomimetic agents or illicit drugs (amphetamines, cocaine, monoamine oxidase inhibitors or phencyclidine) are at risk of developing hypertensive encephalopathy (HE). Drug history
Patients who are taking sympathomimetic agents or illicit drugs (amphetamines, cocaine, monoamine oxidase inhibitors or phencyclidine) are at risk of developing hypertensive encephalopathy (HE).
Irritability Irritability and lethargy are the earliest clinical symptoms which are sometimes neglected by the patient. Irritability
Irritability and lethargy are the earliest clinical symptoms which are sometimes neglected by the patient.
Headache Severe headache is also a common presentation. When the systemic hypertension develops cerebral perfusion pressure increases. In order to prevent the cerebral hyper-perfusion, cerebral auto-regulatory mechanisms cause cerebral vasoconstriction, leading to cerebral ischemia and edema. This in turn increases the intracranial pressure and activates the Cushing reflex and further increases the systemic blood pressure. This process then continues as a vicious cycle, leading to diffuse cerebral dysfunction. Headache
Severe headache is also a common presentation. When the systemic hypertension develops cerebral perfusion pressure increases. In order to prevent the cerebral hyper-perfusion, cerebral auto-regulatory mechanisms cause cerebral vasoconstriction, leading to cerebral ischemia and edema. This in turn increases the intracranial pressure and activates the Cushing reflex and further increases the systemic blood pressure. This process then continues as a vicious cycle, leading to diffuse cerebral dysfunction.
Confusion and coma Due to cerebral dysfunction. Confusion and coma
Due to cerebral dysfunction.
Visual disturbances Blurred vision is a common complain. This is due to diffuse cerebral dysfunction. Visual disturbances
Blurred vision is a common complain. This is due to diffuse cerebral dysfunction.
Seizures Due to diffuse cerebral dysfunction. Generalized seizures are the commonest presentation of HE in children. Often seizures are preceded by headache. Seizures
Due to diffuse cerebral dysfunction. Generalized seizures are the commonest presentation of HE in children. Often seizures are preceded by headache.
Nausea and or vomiting Nausea and vomiting are common complaints. Nausea and or vomiting
Nausea and vomiting are common complaints.
Epistaxis This is a late presentation. Epistaxis
This is a late presentation.
Hematuria and or oliguria Due to hypertensive nephropathy. Hematuria and or oliguria
Due to hypertensive nephropathy.
Symptoms of cerebrovascular accidents Cerebrovascular accidents can occur in HE. Patients can present with hemiplegia, transient cortical blindness or hemiparesis. Symptoms of cerebrovascular accidents
Cerebrovascular accidents can occur in HE. Patients can present with hemiplegia, transient cortical blindness or hemiparesis.
Symptoms of ischemic heart disease Ischemic heart disease is an end organ complication of HE. Patients can present with symptoms of myocardial infarction (severe retrosternal chest pain which radiates to the left arm and neck.) or heart failure (shortness of breath on exertion or at rest, orthopnea). Symptoms of ischemic heart disease
Ischemic heart disease is an end organ complication of HE. Patients can present with symptoms of myocardial infarction (severe retrosternal chest pain which radiates to the left arm and neck.) or heart failure (shortness of breath on exertion or at rest, orthopnea).
Symptoms of aortic dissection Aortic dissection is a complication of the disease. Sudden, severe tearing type of chest, back, or abdominal pain, which radiates to the back, is characteristic of acute aortic dissection. Symptoms of aortic dissection
Aortic dissection is a complication of the disease. Sudden, severe tearing type of chest, back, or abdominal pain, which radiates to the back, is characteristic of acute aortic dissection.

Clinicals - Examination

Fact Explanation
Blood pressure Blood pressure should be measured in both arms. In most patients diastolic blood pressure is more than 120 mm Hg or systolic blood pressure is more than 180 mm Hg. Blood pressure
Blood pressure should be measured in both arms. In most patients diastolic blood pressure is more than 120 mm Hg or systolic blood pressure is more than 180 mm Hg.
Ophthalmoscopic (funduscopic) examination Grade IV retinal changes are associated with hypertensive encephalopathy (papilledema, hemorrhage, exudates, and cotton-wool spots). Papilledema is only present in malignant hypertension. Ophthalmoscopic (funduscopic) examination
Grade IV retinal changes are associated with hypertensive encephalopathy (papilledema, hemorrhage, exudates, and cotton-wool spots). Papilledema is only present in malignant hypertension.
Examination of the nervous system Presence of focal neurological signs, which are commonly transient will favor the diagnosis of stroke. Some patients present with altered mental status, or coma. Examination of the nervous system
Presence of focal neurological signs, which are commonly transient will favor the diagnosis of stroke. Some patients present with altered mental status, or coma.
Examination of the cardiovascular system Peripheral edema, elevated neck veins and dyspnea can be seen if the patient is in cardiac failure. Tachycardia and presence of gallop rhythm with third heart sound (S3) are all suggestive of cardiac failure. After myocardial infarction cardiac murmurs can occur due to valve lesions. Absent or delayed pulsations are suggestive of aortic dissection. Examination of the cardiovascular system
Peripheral edema, elevated neck veins and dyspnea can be seen if the patient is in cardiac failure. Tachycardia and presence of gallop rhythm with third heart sound (S3) are all suggestive of cardiac failure. After myocardial infarction cardiac murmurs can occur due to valve lesions. Absent or delayed pulsations are suggestive of aortic dissection.
Examination of the respiratory system Pulmonary edema, rales, and wheezes can be present with congestive cardiac failure. Pulmonary edema can occur secondary to hypertensive nephropathy as well. Examination of the respiratory system
Pulmonary edema, rales, and wheezes can be present with congestive cardiac failure. Pulmonary edema can occur secondary to hypertensive nephropathy as well.

Investigations - Diagnosis

Fact Explanation
CT or MRI of the head Cerebral edema can be detected. Symmetrical and sub-cortical hyper-intense lesions are seen in MRI and focal hypodensities are seen in CT. CT or MRI of the head
Cerebral edema can be detected. Symmetrical and sub-cortical hyper-intense lesions are seen in MRI and focal hypodensities are seen in CT.

Investigations - Management

Fact Explanation
Full blood count Microangiopathic hemolytic anemia is a known complication of HE. Full blood count
Microangiopathic hemolytic anemia is a known complication of HE.
Urine toxicology screen Helps to diagnose drug induced HE. Urine toxicology screen
Helps to diagnose drug induced HE.
CT or MRI of the head Detects intracranial hemorrhages, which can occur as a complication of HE. CT or MRI of the head
Detects intracranial hemorrhages, which can occur as a complication of HE.
Chest X-ray Chest X-ray helps in diagnosing heart failure (pulmonary edema, Kerley B lines, cardiomegaly, upper lobe diversion, pleural effusions). Cardiomegaly is also seen in chronic hypertension. Aortic dissection is favored by the presence of abnormal aortic contour and or wide aortic silhouette. Chest X-ray
Chest X-ray helps in diagnosing heart failure (pulmonary edema, Kerley B lines, cardiomegaly, upper lobe diversion, pleural effusions). Cardiomegaly is also seen in chronic hypertension. Aortic dissection is favored by the presence of abnormal aortic contour and or wide aortic silhouette.
ECG Detects myocardial infarction. ECG shows evidence of chronic hypertension (left ventricular hypertrophy) and arrhythmia as well. ECG
Detects myocardial infarction. ECG shows evidence of chronic hypertension (left ventricular hypertrophy) and arrhythmia as well.
Cardiac biomarkers Assessment of cardiac biomarkers enables the diagnosis of myocardial infarction. Cardiac biomarkers
Assessment of cardiac biomarkers enables the diagnosis of myocardial infarction.
Urine full report In renal hypertension urine full report will show hematuria and or proteinuria. Urine full report
In renal hypertension urine full report will show hematuria and or proteinuria.
Blood urea nitrogen Elevated in renal hypertension. Blood urea nitrogen
Elevated in renal hypertension.
Serum creatinine Elevated in renal hypertension. Serum creatinine
Elevated in renal hypertension.
Renal biopsy If the initial investigations are suggestive of a renal etiology for hypertension renal biopsy will be helpful for the differentiation of post streptococcal glomerulonephritis and membranoproliferative glomerulonephritis which are common histoligical types. Renal biopsy
If the initial investigations are suggestive of a renal etiology for hypertension renal biopsy will be helpful for the differentiation of post streptococcal glomerulonephritis and membranoproliferative glomerulonephritis which are common histoligical types.

Management - Supportive

Fact Explanation
Health education Patients with chronic hypertension should be advised to exercise regularly and to reduce weight if the BMI is high. Low salt diet, abstinence from alcohol and tobacco use are also helpful. Importance of regular clinic follow up and antihypertensive drug treatment should also be emphasized. Health education
Patients with chronic hypertension should be advised to exercise regularly and to reduce weight if the BMI is high. Low salt diet, abstinence from alcohol and tobacco use are also helpful. Importance of regular clinic follow up and antihypertensive drug treatment should also be emphasized.
Furosemide Effective in pulmonary edema and volume overload (congestive cardiac failure or renal failure). Furosemide
Effective in pulmonary edema and volume overload (congestive cardiac failure or renal failure).
Oxygen Keep the patient at ease especially when pulmonary edema is present. Oxygen
Keep the patient at ease especially when pulmonary edema is present.

Management - Specific

Fact Explanation
Blood pressure control The primary goal of the treatment should be to reduce the blood pressure without reducing the cerebral perfusion pressure, as the cerebral auto regulatory mechanisms take some. Mean arterial pressure should be reduced by 20% and the diastolic blood pressure should be reduced to 100-110 mm Hg during the 1st hour. Blood pressure should not be reduced by more than 95% of the presenting value till 24- 48 hours. Blood pressure control
The primary goal of the treatment should be to reduce the blood pressure without reducing the cerebral perfusion pressure, as the cerebral auto regulatory mechanisms take some. Mean arterial pressure should be reduced by 20% and the diastolic blood pressure should be reduced to 100-110 mm Hg during the 1st hour. Blood pressure should not be reduced by more than 95% of the presenting value till 24- 48 hours.
Sodium nitroprusside This is the drug of choice in HE and administered dose is 0.5 μg/kg/min. Sodium nitroprusside dilates both arteries and veins and reduces myocardial oxygen demand. Sodium nitroprusside
This is the drug of choice in HE and administered dose is 0.5 μg/kg/min. Sodium nitroprusside dilates both arteries and veins and reduces myocardial oxygen demand.
Nitroglycerin Allows rapid reduction of blood pressure by its venodilatory action. When cardiac failure and or myocardial ischemia are associated with HE nitroglycerin is useful as it can improve both conditions. The use should be limited to 24 to 48 hours as tolerance to nitroglycerin develops. Nitroglycerin
Allows rapid reduction of blood pressure by its venodilatory action. When cardiac failure and or myocardial ischemia are associated with HE nitroglycerin is useful as it can improve both conditions. The use should be limited to 24 to 48 hours as tolerance to nitroglycerin develops.
Nicardipine A dihydropyridine-derivative calcium channel blocker, with cerebral and cardiac vasodilatory effects. It is effective in reducing cerebral ischemia as well. Reflex tachycardia is a side-effect of the treatment. Nicardipine
A dihydropyridine-derivative calcium channel blocker, with cerebral and cardiac vasodilatory effects. It is effective in reducing cerebral ischemia as well. Reflex tachycardia is a side-effect of the treatment.
Fenoldopam A dopaminergic-1 receptor agonist which causes arterial vasodilatation. By acting on the kidneys it increases renal blood flow and natriuresis. Fenoldopam
A dopaminergic-1 receptor agonist which causes arterial vasodilatation. By acting on the kidneys it increases renal blood flow and natriuresis.
Hydralazine Hydralazine acts very slowly and maximum blood pressure reduction is achieved after about 30minutes, making hydralazine less effective in HE. Hydralazine
Hydralazine acts very slowly and maximum blood pressure reduction is achieved after about 30minutes, making hydralazine less effective in HE.
Labetalol Labetalol is a nonselective beta-blocker which reduces the systemic blood pressure without affecting the cerebral perfusion pressure. Labetalol
Labetalol is a nonselective beta-blocker which reduces the systemic blood pressure without affecting the cerebral perfusion pressure.
Phentolamine This is an alpha blocker, used to treat hypertension secondary to pheochromocytoma and secondary to cocaine or other sympathomimetic drug use. Phentolamine is administered as 5 to 10 mg, boluses. Phentolamine
This is an alpha blocker, used to treat hypertension secondary to pheochromocytoma and secondary to cocaine or other sympathomimetic drug use. Phentolamine is administered as 5 to 10 mg, boluses.

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